According to the prior art, hollow charges—also referred to in the art as “hollow shaped charges”—for use in blasting applications in boreholes are packed in pairs in a pack. No protection against fragments is provided. Usually, the whole packaging is made of cardboard and, if necessary, a vacuum bag to protect against moisture.
The packaging is only suitable to a limited extent for capturing fragments, which are generated in the packaging when a hollow charge is initiated. The criteria which are specified by the official 6(d) test are not fulfilled.
As well as the existing criteria of the official 6(a), 6(b) and 6(c) test, the packaging must also withstand the “Test 6(d) Unconfined Package Test (UN)” in the “UN Manual of Tests and Criteria”.
The requirements of the official 6(d) Unconfined Package Test dictate that all hazardous effects caused by the reaction of a hollow charge in the packaging must be restricted to the packaging.
Indications of a hazardous effect outside the packaging are:
(a) Denting or perforation of a verification plate under the packaging;
(b) A flash or a flame is produced, which ignites a material lying next to the packaging, such as a sheet of paper (80±10 g/cm2) at a distance of 25 cm from the packaging;
(c) Tearing of the packaging and ejection of the contents of the packaging, or
(d) An ejected part, which completely punctures the packaging (an ejected part or fragment retained or sticking in the wall of the packaging is not considered to be hazardous).